Integrated reflectography and thermography for wooden paintings diagnostics

The need of inspecting a masterpiece of fine art without affecting it led to develop non destructive methods of investigation. In the field of art conservation, several diagnostic techniques are being widely used to inspect works of art, giving different but complementary results. The present work deals with two of these methods, reflectography and thermography, both techniques examining objects in the infrared spectrum but in different wavelength bands. Their integrated data potentially provide a powerful tool for mapping hidden features and alterations of artworks. This was confirmed during the inspections of a 13th century panel painting under restoration at the Opificio delle Pietre Dure laboratories (Florence, Italy). A graphical user interface was also designed to aid operators in the field of conservation dealing with the results of the two IR methods. Many options such as image adjustment, comparison, overlaying and transparency variation, in addition to thermographic elaborations, have been made available to users. Imaging data integration provides a multi-layered and multi-spectral representation of the painting that yields a comprehensive diagnosis confirms the anomalies individuation and reduces the ambiguities of information coming from a single diagnostic method.     

Financial returns,price determinants,and genre effects in American art investment

Past studies on art investment generally have found that returns are low and risk is high. In this study we find that the return to art investment is more in line with traditional investments and thus the cost for consumption associated with art seems fairly small. Employing a large sample of paintings by 66 American artists sold at auction between 1971–1992, average returns are found to be over 9 per cent and 3 per cent in nominal and real terms, respectively. The model employs a log linear price regression estimated by pooled cross section and time series data, and allows rates of return as well as hedonic values for various painting and auction attributes to be estimated. These include size, media, age of execution, authenticity of the work, and auction month and house. In addition, rates of return are differentiated by artist, time period of investment, price range and genre of the painting. The findings indicate significant sensitivity of rates of return to these data stratifications.This paper was presented at the 9th international conference of the Association for Cultural Economics, held in Boston, May 8–11, 1996.     

Comparison of hot-air and low-radiant pew heating systems on the distribution and transport of gaseous air pollutants in the mountain church of Rocca Pietore from artwork conservation points of view

The concentrations of CO₂, CO, formaldehyde (H₂CO) and water vapour were simultaneously monitored in various sections of a mountain church situated in the village of Rocca Pietore in the Italian Alps. The performance of a conventional, hot-air heating system and a novel design for heating the church, consisting of low-temperature heating elements, such as electrically heated pews and carpets, were compared for the supply, transport and removal of gases, the deposition and/or transformation of which may affect the preservation of displayed works of art. Experiments with sulphur hexafluoride (SF₆) tracer-gas showed a considerable influx of external air through the hot air carrier ducts of the old heating system, and also the leakage of the internal air mostly via the apertures of the doors. The ventilation rates for the total volume of the church with the hot-air heating system (on for 1.5 h), the new heating system (on for 2 h), and without heating were calculated to be 0.25, 0.18, and 0.13 h⁻¹, respectively. Without heating, a nearly homogeneous distribution of gases has been observed along both the horizontal and the vertical cross-sections of the church. Immediately after switching on the hot-air heating system, the levels of CO₂ and water vapour showed a sharp increase. After turning this system off, the levels of gases showed a slow fall and they developed a highly non-homogeneous spatial distribution indoors for many hours. In the upper region of the church, being airtight, higher concentrations of the pollutants could be detected. The low levels of CO and H₂CO, mostly originating from incense burning during services, were correlated to that of CO₂. The hot-air heating system has been proved to present a potential deterioration risk to artworks, as it increases the supply, transport and deposition probability of air pollutants. On the other hand, the novel, symmetrical heating system eliminates these undesirable effects, thus its application is advantageous to all churches involved in the preservation of works of art.     

An analytical investigation of the painting technique of Italian Renaissance master Lorenzo Lotto

This paper presents the first extensive investigation of the composition of both the organic and inorganic media used by Lorenzo Lotto, one of the outstanding artists of the Italian Renaissance in the early 16th century. By investigating four paintings from The State Hermitage Museum collection (Saint-Petersburg, Russia), new insights into the artist's painting techniques were obtained, which contribute to our understanding of the transition from egg tempera to oil painting techniques that took place in Italian paintings between the 15th to the mid 16th century. Inorganic materials were determined using SEM-EDX and PLM, revealing information on the artist's palette. Of particular note was the powdered colourless glass found in the priming layer of the Madonna delle Grazie, which was most likely used as dryer. Organic materials were analysed in individual paint layers using GC-MS, and revealed a mature use of drying oils as paint binders, skilfully mixed with other organic materials and inorganic driers, to obtain the desired aesthetical and technical qualities of the paint. The study revealed that Lotto used the tempera grassa technique through most of his creative life.     

Significance of studying the petrography and mineralogy of the geological environment of old rupestrian churches to prevent their deterioration. A case study from the South Carpathians

This paper provides new insights into understanding the causes of deterioration of the Corbii de Piatra rupestrian church and shows the significance of studying the geological environment of historical rock-cut settlements when undertaking preservation and restoration actions. The Corbii de Piatra church is one of the few rupestrian churches remaining in Romania and is an important part of the country's heritage. The church is carved in a stratum of polymictic sandstone of Oligocene age, which is part of the Getic Depression, located in the southern part of the South Carpathians. In the 14th century the interior walls of the church were decorated with mural paintings of a high artistic value. Over the centuries, the church's walls and mural paintings have been negatively affected by a series of physicochemical processes. These processes were studied through field investigations and laboratory analyses carried out between October 2007 and November 2010. The investigations revealed that tectonic fissuring and the structural anisotropy of the rock facilitate the infiltration of meteoric water through the walls into the interior of the church, from north to south, maintaining a high-level of humidity in the northern wall and in the interior of the church. The most harmful effects observed were: (i) the partial hydrolysis of the feldspars through reaction with water from the pores, producing a friable mass of phyllosilicates which led to a superficial disaggregation of the rock and to a diminished cohesion between the rock and the mortar of the fresco, (ii) the reprecipitation of the gypsum as efflorescences on the northern wall and ceiling, covering the mural painting in localized areas, as a result of the transportation of the gypsum by water from the upper strata, (iii) the alteration of the cinnabar pigment, as a result of water penetration by diffusion through the fresco from the wet rock to the pictorial layer (the secondary effect observed being the formation of sulfuric acid, which further reacted with the carbonate from the fresco to form gypsum), (iv) the development of biotic crusts, predominately algal, on the interior wet walls, which, facilitated by the permanent high humidity and the semi-obscurity of the interior of the church, have covered large surfaces of the fresco. Compared to the interior, the exterior vertical walls have been exposed to prolonged daily and seasonal variations of temperature and humidity. These variations have caused repeated variations in the volume of the sandstone, leading to contraction fissuring and peeling of the vertical walls. Any future procedures that might be used to conserve the church should strive to reduce the humidity of the sandstone in the interior walls.     

Art collections and taste in the Spanish <Emphasis Type="Italic">Siglo</Emphasis><Emphasis Type="Italic">de Oro</Emphasis>

We analyze art pricing in a unique dataset on Madrid inventories between 1600 and 1750. We estimate a price index for the Spanish art market that is used for a general historical analysis of art during this period, showing a large increase in the real price of paintings during the XVII century. Then we examine the price differential between domestic and foreign paintings: At the beginning of the century domestic production was priced substantially below imported paintings, but the price gap was gradually reduced during the century. We argue that such a price convergence was not the fruit of variations in real exchange rate, relative supply or home bias, but was associated with increasing prices for the new domestic painters of the XVII century. Increasing remuneration for painting may have induced artistic innovations by domestic producers and created the conditions for the development of the Siglo de Oro of Spanish art.     

A Note on Financial Risk, Return and Asset Pricing in Australian Modern and Contemporary Art

In this note, 30,227 paintings by fifty well-known modern and contemporary Australian artists sold at auction over the period 1973–2003 are used to construct a hedonic price index. The attributes included in the hedonic regression model include the name, age and living status of the artist, the number of works sold, the size and medium of the painting, and the auction house, month and year in which the painting was sold. The results indicate that returns on Australian modern and contemporary art averaged nearly five percent over the period with a standard deviation of sixteen percent. The results also show that a ten percent increase in the Australian stock market is associated with a 3.4 percent increase in the art market. Generally, artworks by artists deceased at the time of auction, larger works, works executed in oils, and those auctioned by Sotheby's or Christies in July or August are associated with higher prices.     

Age–price profiles for Canadian painters at auction

We conduct an empirical analysis of the effect on the auction price of a Canadian painting of the age of the painter at the time of creation of the painting. We consider over two hundred artists, active over the entire history of Canadian art, who are pooled in the estimation of a hedonic regression in which a polynomial function in age enters as a regressor along with several other control variables. We consider the possibility that the age–price relationship has changed over time by: (a) estimating separate age–price functions for three generational groups of artists—those born before 1880, between 1880 and 1920, and after 1920 and thus coming of age in the world of post-war ‘contemporary art’ and (b) estimating a parameterization where the shape of the age–price profile is permitted to change continuously depending on the year of birth of the artist. Our principal result is that artists born more recently tend to ‘peak’ earlier in their careers than those of previous generations.     

The scientific investigation for the study and conservation of the wooden model of S. Maria della Consolazione's church (Todi,Italy)

The focus of this work is the wood polychrome model of the church of S. Maria della Consolazione in Todi, an artefact whose author and historical events are not completely known except a general reference to the construction period of the church (1508–1607 AD). In this study, original and additional materials were examined in order to provide a deeper understanding of the painting and assembly techniques, and a greater awareness of how well preserved the object is, as well as an analysis of previous preservation and conservation interventions. The samples from the painted surfaces were examined by means of micro-Raman spectroscopy, fourier transform infrared (FTIR) spectrometry and internal microstratigraphic analysis. Thin sections of the wood samples were examined under an optical transmission light microscope in order to identify the botanical species. The results shown in this paper suggest the possibility that the original painted layers are made of calcium carbonate white, red ochre and indigo and they were applied by protein binder without any ground layer. Some non-original pigments were found on the model surface like Prussian blue and chrome yellow. Concerning wood components, poplar was characterized both in the original and non-original parts of the model whereas pine species were detected only in the restoration elements.     

GPR technique as a tool for cultural heritage restoration: San Miguel de los Reyes Hieronymite Monastery, 16th century (Valencia,Spain)

This paper describes GPR (ground penetrating radar) surveys performed inside the crypt of the San Miguel de los Reyes Monastery (1546–1835) in order to detect the exact location of its founders' remains, the Dukes of Calabria (16th century). This Monastery was erected to house their family mausoleum and the bodies of the founders were buried near the high altar of the church (1645). However, in the 18th century, the tombs were exhumed to provide them with a worthier burial site: the crypt below the high altar. There is no documentation specifying the exact location of the tombs inside the crypt. Therefore, in order to reveal the exact location of the tombs the GPR survey was conducted inside the crypt.In our specific study, the available historical documentation led us to suppose that the Dukes of Calabria's remains were inside their mausoleums. However, after having performed the GPR analysis, we discovered that the mausoleums were solid and not hollow. The project required data collection on four areas in the crypt: the altar crypt, the Fernando de Aragón mausoleum, the Germana de Foix mausoleum and the floor between the two mausoleums and the altar.In this study, we have processed the GPR records in three different ways: the radargrams were processed in a standard manner, a detailed spectral analysis of all anomalous areas was carried out, and finally a 3D representation was generated. After this complete analysis we concluded that the bodies were not located inside their mausoleums, because they were shown to be solid. Besides, a burial site was located in the crypt subsurface near the Germana de Foix mausoleum, in which four different elements could be identified. Two of them may well be the tombs of the Dukes of Calabria and the other two the tombs of the Germana de Foix sisters.The results obtained in this survey are a good example of GPR application as an efficient and respectful tool for use in Cultural Heritage restoration studies, providing it with a very useful technique for similar projects such as those carried out in the restoration of historical buildings and those in which the elements to be examined are beneath a shallow coating of material.     

The impact of electric overhead radiant heating on the indoor environment of historic churches

The impact of electric overhead radiant heaters on the microclimate, air flows, transport and deposition of suspended particulate matter (SPM) was monitored between March 2004 and March 2005 in the historic churches of Saint Michael Archangel in Szalowa and Saint Catherine in Cracow (Poland). The measurements show that although irradiation at the floor level increases temperature and reduces relative humidity in the interior of the church, the effect out of the heated zone and for the surfaces sheltered from irradiation is very limited, i.e. their extent is comparable with natural fluctuations inherent to the local climate of the church. The radiant heaters proved to generate little convectional flow of the air. Therefore, the heating system was not found to increase the concentration of SPM indoors; in particular, no re-suspension of particles already present in the church was observed. This work has demonstrated that the overhead radiant heaters are capable of providing localised heat to the areas where people congregate without adversely affecting painted walls and the works of arts displayed in churches. Care, however, should be taken that sensitive works of art are not exposed to the direct infrared radiation.     

The palette of the Macchia Italian artist Giovanni Fattori in the second half of the xixth century

Giovanni Fattori (Livorno 1825–Firenze 1908) is the most representative artist of the Macchiaioli's current, an early group of Italian plein-air artists, whose work anticipates, in the xixth century, that of their younger contemporaries, the French Impressionists. The study, performed by a multidisciplinary team made up of scientists and conservators, presents the results of the scientific characterization carried out on a group of 10 paintings made by Fattori between 1854 and 1893 and shows the way he used complex mixtures of a large variety of traditional and synthetic pigments, ranging from lead white, found pure and also extended with calcium carbonate, natural barite and gypsum to zinc white, from red ochre to cinnabar and vermilion, from yellow ochre and Naples yellow to chrome yellow, cadmium yellow and zinc yellow, combined with many other ones reported in details. This paper highlights the evolution of his painting technique during a time of great technological and social innovations and puts forward some hypothesis on his awareness about manufactured pigments, i.e. tube paints recently introduced into the artists’ circles. The wide range of pigments and their different quality among the same synthetic products suggest that the artist used all the available materials, and that picking out the pigments he retained the early xixth century artists techniques, such as the use of mineral earths and Prussian blue, similarly to his contemporary Italian artists Federico Zandomeneghi and Telemaco Signorini, but he also experimented new and peculiar pigment mixtures in the making of “colored darks” and an innovative use of the grounds in the final composition, that are also distinctive features of the French Impressionists. This work is aimed at contributing to overcome the lack of a comprehensive overview on the widespread historical and scientific data collected up to now on the Italian paintings in the xixth century, which has been severely underestimated with respect to previous art movements.     

An integrated approach to the study of a reworked painting “Madonna with child” attributed to Pietro Lorenzetti

The painting “Madonna with Child”, attributed to Pietro Lorenzetti (14th century) and reworked around the middle of the 16th century, was studied by several techniques in order to characterize the materials used in the original and in the repainted areas. FORS, light microscopy, ESEM-EDX, ToF-SIMS and GC-MS were used. Red ochre and raw sienna earth were identified by FORS in the original parts of the painting. On the repainted parts of the panel, cinnabar, ultramarine blue and lead white were found. By means of GC-MS and ToF-SIMS measurements it was possible to identify the organic binding media used in the preparatory and painted layers.     

The Russian avant-garde painting palette: Documentary and physicochemical codification of organic colorants

In the present article an attempt is made to elucidate the organic colorants commonly encountered in the Russian avant-garde painting palette by a combined art historical, documentary and physicochemical investigation, and to examine the influence of environmental factors on the chromatic profile originally sought by the artist. The overall approach based on written sources is confirmed by measurements on relevant paintings. The documentary research deals with the influences of Orthodox iconography, folkloric art, and occidental modernist tendencies on the Russian avant-garde palette, and studies the effects of contradictory historical processes in the chromatic profile of individual paintings. In the experimental section a series of colorants are investigated concerning the effects of accelerated ageing on experimental painting tables, prepared as watercolor and gouache layers on paper ground. The resulting samples are subjected to colorimetric and spectroscopic measurements, and analogous analytical procedures are applied on samples taken from selected paintings. A systematic comparative study of all data permits evaluation of the materials used in terms of their stability towards extrinsic factors, and proposal of degradation routes in order to assist museum curators and conservators in every concrete case related to the broad spectrum of pigments examined.     

Consolidation and protection by nanolime: Recent advances for the conservation of the graffiti,Carceri dello Steri Palermo and of the 18th century lunettes,SS. Giuda e Simone Cloister,Corniola (Empoli)

Nanolime dispersed in 2-propanol was extensively used for the consolidation of wall paintings. The knowledge of the advances of this methodology dealing with all the possible effects associated with the nanolime new material in conservation is fundamental to assess and improve the technique. In this paper, four different dispersions of Ca(OH)₂ nanoparticles were characterised by Small Angle X-rays Scattering technique (SAXS) and Transmission Electron Microscopy (TEM) in order to achieve information on size, shape, polydispersity, agglomeration, and crystal structure (by SAED patterns) of the particles. Once characterised, the dispersions were tested in two different case studies, the Carceri dello Steri in Palermo with their graffiti and the 18th century lunettes at the SS. Giuda e Simone Cloister, Corniola (Empoli) with their lime-based mural paintings. The treated samples were characterised in relationship to either their morphology and surface chemical composition by Scanning Electron Microscopy coupled with Energy Dispersive X-rays spectroscopy (SEM-EDX), or their water absorption and mechanical properties (resistance to material abrasion). The results obtained showed that all the dispersions were nanometrically structured and their application succeeded in recovering the mechanical properties of the painting or graffito layers, not altering their permeability to water and keeping perfectly the wall transpiration. However, the dispersions constituted of the nanoparticles obtained via a synthesis able to control size and shape of the Ca(OH)₂ particles resulted in a better performance in situ, even if the differences found by SAXS and TEM were slight.     

Defects induced by gamma irradiation in historical pigments

The paper presents our results concerning a complex investigation by reflectance spectroscopy (RS) and Electron Paramagnetic Resonance (EPR) of the defects induced by gamma irradiation in 22 different historical pigments. Gamma irradiation is used to destroy microflora and insects which are involved in biodeterioration processes of art works such as paintings. At the same time, it can induce defects i.e. color centers which are likely to modify the original painting colors by altering the embedded pigments. Accordingly, RS was used to quantify, by means of CIELAB color space, the contribution of irradiation defects to the pigments color changes, while EPR spectroscopy, in view of paramagnetic properties of color centers, was used to confirm their presence after irradiation. Our investigations showed that, excepting marble dust whose color alteration was still observable after 3 months, color changes induced by irradiation in all other pigments disappeared after about 30–40 days. In addition, RS as well as EPR measurements suggest that color changes are related to irradiation color centers, this finding being confirmed by the coincidence, within experimental uncertainties, of the half-life time color changes as obtained by these methods.     

Influence of different types of heating systems on particulate air pollutant deposition: The case of churches situated in a cold climate

The influence of three types of heating systems (electrically heated pews, hot air blow heating and provisory electrical (infrared) heaters) on the transport and deposition of particulate pollution was investigated in churches located in a cold climate. Two methods were applied for the analysis of aerosol samples collected inside and outside the churches: energy dispersive X-ray fluorescence analysis and electron probe X-ray microanalysis. The results show that all the heating systems re-suspend the particulate matter brought from outside. However, the extent of re-suspension of the systems is different. It is also shown that the hot air blow heating, – the oldest design of the studied systems, – warming the church by blowing in hot air could generate organic particles. Such particles can cause soiling, and/or blackening of works of art present in the church. The application of this heating system also provoked the deterioration of the plastered walls, thus leading to the creation of an extra internal source of Ca. The other two heating systems (more modern) demonstrate less influence on the works of art regarding aerosol deposition.     

薪火相传 飞彩凝辉——记“为艺术战—浙江美术馆藏品展”

浙江人文荟萃,艺术创作尤其繁荣,自南宋以来即为中国书画重镇。"南宋四家"(李唐、刘松年、马远、夏圭)、赵孟頫、黄公望、徐渭、陈洪绶、任伯年、吴昌硕等都是在中国美术史上无论如何也绕不开的大师级人物。1927年11月,蔡元培选址杭州西子湖畔,于次年建立了中国第一所综合性国立高等艺术学府——国立艺术院(中国美术学院前身)。从此,20世纪的浙江美术发展历程就与这所高等学府相辅相成,可以说是"同呼吸,共命运"。浙江为中国美院的发展提供了良好的传统艺术积淀和氛围,以及众多的优秀师资、生源,而中国美院     

From Van Gogh's museum to the temple at bassae: heidegger's truth of art and schapiro's art history

This essay revisits Meyer Schapiro's critique of Heidegger's interpretation of Van Gogh's painting of a pair of shoes in order to raise the question of the dispute between art history and philosophy as a contest increasingly ceded to the claim of the expert and the hegemony of the museum as culture and as cult or coded signifier. Following a discussion of museum culture, I offer a hermeneutic and phenomenological reading of Heidegger's ‘Origin of the Work of Art’ and conclude by taking Heidegger's discussion of the strife between earth and world to the site of the ancient temple of Apollo Epicurius at Bassae as an example of the insistent foreclosure of the ancient work of art and the conflicts of the pervasive efforts of modern conservation.